In Fig.REF  we also show an estimate of the surface brightness in the direction of the cavity center due to the thermal bremsstrahlung of the high temperature gas inside the cavity and of the external ICM present along the line of sight. This last quantity has been calculated assuming the presence of a gas with constant temperature of 5.5 keV and with the double beta radial profile derived from X-ray observations (see [1]} for details), extended until the virial radius of 2.23 Mpc [2]}, along the line of sight at the distance of 150 kpc from the cluster center, and excluding from the integration along the line of sight the cavity region, approximated as a sphere with radius of 100 kpc. The bremsstrahlung produced by the high temperature gas inside the cavity results to be much lower than the one from the ICM, as expected because of its lower density, higher temperature, and smaller size. The bremsstrahlung produced by the ICM is instead dominant on the SZE produced by the non-thermal electrons at frequencies higher than \(\sim 2\times 10^{15}\)  Hz, i.e. in the far ultraviolet band.
